/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.naming.factory;

import javax.mail.Session;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimePartDataSource;
import javax.naming.Context;
import javax.naming.Name;
import javax.naming.RefAddr;
import javax.naming.Reference;
import javax.naming.spi.ObjectFactory;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Properties;

/**
 * Factory class that creates a JNDI named javamail MimePartDataSource
 * object which can be used for sending email using SMTP.
 * <p>
 * Can be configured in the Context scope
 * of your server.xml configuration file.
 * <p>
 * Example:
 * <p>
 * <pre>
 * &lt;Resource name="mail/send" auth="CONTAINER"
 *           type="javax.mail.internet.MimePartDataSource"/>
 * &lt;ResourceParams name="mail/send">
 *   &lt;parameter>&lt;name>factory&lt;/name>
 *     &lt;value>org.apache.naming.factory.SendMailFactory&lt;/value>
 *   &lt;/parameter>
 *   &lt;parameter>&lt;name>mail.smtp.host&lt;/name>
 *     &lt;value>your.smtp.host&lt;/value>
 *   &lt;/parameter>
 *   &lt;parameter>&lt;name>mail.smtp.user&lt;/name>
 *     &lt;value>someuser&lt;/value>
 *   &lt;/parameter>
 *   &lt;parameter>&lt;name>mail.from&lt;/name>
 *     &lt;value>someuser@some.host&lt;/value>
 *   &lt;/parameter>
 *   &lt;parameter>&lt;name>mail.smtp.sendpartial&lt;/name>
 *     &lt;value>true&lt;/value>
 *   &lt;/parameter>
 *  &lt;parameter>&lt;name>mail.smtp.dsn.notify&lt;/name>
 *     &lt;value>FAILURE&lt;/value>
 *   &lt;/parameter>
 *   &lt;parameter>&lt;name>mail.smtp.dsn.ret&lt;/name>
 *     &lt;value>FULL&lt;/value>
 *   &lt;/parameter>
 * &lt;/ResourceParams>
 * </pre>
 *
 * @author Glenn Nielsen Rich Catlett
 */

public class SendMailFactory implements ObjectFactory {
	// The class name for the javamail MimeMessageDataSource
	protected final String DataSourceClassName =
			"javax.mail.internet.MimePartDataSource";

	@Override
	public Object getObjectInstance(Object refObj, Name name, Context ctx,
	                                Hashtable<?, ?> env) throws Exception {
		final Reference ref = (Reference) refObj;

		// Creation of the DataSource is wrapped inside a doPrivileged
		// so that javamail can read its default properties without
		// throwing Security Exceptions
		if (ref.getClassName().equals(DataSourceClassName)) {
			return AccessController.doPrivileged(
					new PrivilegedAction<MimePartDataSource>() {
						@Override
						public MimePartDataSource run() {
							// set up the smtp session that will send the message
							Properties props = new Properties();
							// enumeration of all refaddr
							Enumeration<RefAddr> list = ref.getAll();
							// current refaddr to be set
							RefAddr refaddr;
							// set transport to smtp
							props.put("mail.transport.protocol", "smtp");

							while (list.hasMoreElements()) {
								refaddr = list.nextElement();

								// set property
								props.put(refaddr.getType(), refaddr.getContent());
							}
							MimeMessage message = new MimeMessage(
									Session.getInstance(props));
							try {
								RefAddr fromAddr = ref.get("mail.from");
								String from = null;
								if (fromAddr != null) {
									from = (String) ref.get("mail.from").getContent();
								}
								if (from != null) {
									message.setFrom(new InternetAddress(from));
								}
								message.setSubject("");
							} catch (Exception e) {/*Ignore*/}
							MimePartDataSource mds = new MimePartDataSource(message);
							return mds;
						}
					});
		} else { // We can't create an instance of the DataSource
			return null;
		}
	}
}
